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A. H. STODDARD. v LOCKING DEVICE FOR THE PLASKS OF DENTAL VULOANIZ BRS.No. 436,009.;

Patented Sept. 9, 1890.

UNITED STATES PATENT ,OFFTGE.

ARTHUR H. STODDARD, OF BOSTON, MASSACHUSETTS, ASSIGNOR TO THE BOSTONDENTAL MANUFACTURING COMPANY, OF SAME PLACE.

LOCKING DEVICE FOR THE FLASKS OF DENTAL VULOANIZERS.

SPECIFICATION forming part of Letters Patent No. 436,009, datedSeptember 9, 1890.

Application filed December 5, 1889- Serlal No. 332, 7 N mod l-l To allwhom it may concern:

Be it known that I, ARTHUR H. STODDARD, a citizen of the United States,and a resident of Boston, in the county of Suffolk and State 5 ofMassachusetts, have invented certain new and useful Improvements inLooking Devices for the Flasks of l) ental Vulcanizers, of which thefollowing is a specification.

My improvements are directed particularly 10 to the devices whereby thevulcanizing-flask is kept together under the necessary pressure duringvulcanization.

In the accompanying drawings, Figure 1 is a plan View of the top of avulcanizer with operating-handle removed; Fig. 2, a vertical section onthe line 00 0c of Fig. I of the vulcanizer, including thevulcanizing-flask in position therein; and Fig. 3 is a plain View of theflask and the device by which it is held together.

As a means of clamping and holding the two parts of the flask together,I employ a spring A, formed of a piece of spring metal, having a lowermember a embracing the botz 5 tom of the flask and an upper member toextending over the top of the flask. In conjunction With this uppermember I provide locking-cams B, pivotally attached to the said uppermember and bearing upon the top of the flask. These locking-cams, whenthrown in one direction, force the cover or upper portion of the flasktightly against the lower portion, and the apparatus is in thiscondition during vulcanization. WVhen it is desired to open the flask,this may readily be done by throwing thelocking-cams in the reversedirection, or so as to unlock them,when the flask can be easily takenout and opened. I have shown two locking-cams arranged at either side ofthe upper member a of the clamping-spring. A single cam placed in thecenter of the end of the spring might be employed,but would not, in myjudgment, operate as satisfactorily.

Furthermore, by pivoting the levers upon the cover, as distinguishedfrom pivoting them upon the pot, as has heretofore been done, I obtainan important practical advantage, in that when the cover with the leversis removed and placed one side no parts are left hanging 5o loosely uponthe pot to get in the way of the operator or to interfere with hishandling of it.

I am aware that spring-containing devices have been employed heretoforefor holding the parts of a flask together duringvulcanization, and Imake, therefore, no claim, broadly, to the use of a spring for thispurpose. I believe, however, that the specific construction ofspring-plate operated byalocking and unlocking cam is novel with myselffor the purposes stated.

I' claim The herein-describedimprovement in vulcanizers, consisting ofthe spring A, havinga lower member 0; to embrace the under side of theflask and an upper member a extending over the upper portion of theflask, and locking-cams pivotally connected with the said upper memberof the spring and arranged to bear against the upper portion of theflask, whereby the parts of the flask maybe locked together underspring-pressure and may be released from pressure when desired.

In testimony whereof I have hereunto subscribed my name this 29th day ofNovember,

ARTHUR H. STODDARD.

Witnesses:

ELLEN B. TOMLINSON, JOHN H. TAYLOR.

